Ginkgo biloba.
Ginkgo has become a "hot" topic. From television programs to magazine articles and from teas and tinctures to a host of ginkgo-related products, this herb has been getting a lot of attention. According to a recent report, ginkgo was one of the top-selling herbs in the United States throughout 1997.
Is Ginkgo something you need to know about? Perhaps you have been wondering what it does, what it can do for you, and whether it is safe to use as a supplement. This book should be able to answer all your questions. We'll start with a description of the plant itself.
The Ginkgo Tree.
The natural product extract that is receiving all this attention comes from the ginkgo, or maidenhair, tree. This unique tree, known scientifically as Ginkgo biloba L. is considered a "living fossil" because it existed at least 230 million years ago, in the early Paleozoic era. Dinosaurs probably snacked on the same tree you can find along the streets of major cities today. There aren't many plants or animals from that era that still survive today.
Ginkgo is the sole survivor of a prehistoric family of trees that thrived in Europe until the last ice age, when the ginkgo family was completely wiped out as huge sheets of ice swept across the continent. The ginkgo tree survived in China and was later cultivated by Chinese monks.
The ginkgo tree is extremely hardy, and individual trees can be very long-lived. Some have been known to survive for more than 1,000 years. One estimate even puts the life span of an individual ginkgo at 2,000 to 4,000 years!
Why Is It Called Ginkgo?
The name ginkgo comes from the nut (technically called the "ovule") produced by the female ginkgo tree. This primitive yellow-green seed ripens to an orange-brown, foul-smelling, and fleshy "fruit" that encloses a silvery inner kernel. This kernel is what actually gives ginkgo its common name. The term comes from the Japanese word ginkyo: gin meaning silver, and kyo meaning apricot. This "silver apricot" has been specially prepared, usually by boiling or roasting, and eaten in the Orient for thousands of years.
The species name, biloba, comes from the tree's un- usual leaves. The fan-shaped leaves of ginkgo have an indentation or a split down the middle. Because of this split, botanists consider it two-lobed, or bilobed.
Arising from the Ashes.
The legendary hardiness and survivability of the ginkgo tree was demonstrated in Hiroshima, Japan, in the ‘40s. A ginkgo tree located in the city center was incinerated along with all other plants and animals when the atomic bomb detonated on August 6, 1945. The following year, a new ginkgo tree sprouted where the old one had been and grew into a normal, full-sized tree!

What Does the Ginkgo Look Like?
Although you might not have been aware of it, you've probably already seen a ginkgo tree. Because this specimen is so hardy that it's very tolerant of pollution and resistant to insect attack, ginkgo is popular with urban planners. Consequently, these trees can be found in many large cities throughout Europe and North America.
Like most trees, the ginkgo is easiest to identify by its leaves (see figure 1). The distinctive, fan-shaped leaf can grow to a size large enough to just about cover the palm of your hand. The leaf fan extends from a stalk that comes directly from the stem of the tree. As mentioned earlier, the leaf fan usually has a split or indention in the middle, creating the two-lobed effect for which the tree was named. Note that the smaller and younger leaves of the ginkgo tree may not be split and that older ones may have more than a single indentation.
If you compare a ginkgo leaf to the leaves of other trees, you'll certainly notice the difference. Ginkgo leaves lack the fine cross-vein structure of other leaves and instead have veins that radiate or "fan" out from the base of the leaf to its edges. The effect is much like that of a Chinese fan.
The ginkgo tree is deciduous, which means that sheds its leaves in the fall, like many other trees do. Green in the summer, the ginkgo' s leaves turn a glowing yellow the autumn.
Ginkgos can grow to 130 feet in height. Trees that haven't yet reached maturity are shaped like a cone. Without their leaves, younger branches look like they've been fashioned from coat hangers, as they split off the main trunk at almost right angles. As ginkgo trees get older and larger, they develop more of a spreading crown. The ginkgo tree is so distinctive that once you've identified your first ginkgo, you'll likely be able to identify others even after they've lost their leaves.
What Is in Ginkgo?
Green plants are virtual chemical factories, and the gink tree is no exception. The ginkgo spends its days absorbing sunlight, water, and nutrients from the soil and producing chemicals that help it grow. Two types of chemicals produced by the ginkgo tree are of particular interest to us: flavonoids and terpenes.
Flavonoids are common in our everyday lives. In fact, if you eat 3 to 5 servings of fruits and vegetables daily, then you're probably consuming a gram of these substances a day, which can be beneficial to your health. Many flavonoids have an antioxidant effect similar to that of vitamins E and C. Flavonoids, which are found in all flowering plants, are the chemicals that give leaves their fall colors. Most of the flavonoids found in ginkgo are commonly found in many other plants.
Terpenes, another class of chemicals found in plants, are substances that help produce a plant's characteristic odor. The scent of a rose or the fragrance of an orange blossom are both the result of evaporating terpenes. Ginkgo produces certain unique terpenes, called ginkgolides and bilobilade. Although many other chemical substances are found in ginkgo, modern research into the plant's medicinal properties has concentrated mostly on flavonoids and terpenes.
What Was Ginkgo Used for Historically?
The medicinal use of ginkgo goes back about 5,000 years to the beginning of traditional Chinese medicine. In the Pen Ts'ao Ching, China's first-known classic herbal book, ginkgo seeds and fruit were recommended for treating conditions involving the heart and lungs. In the 1700s, ginkgo was brought to Europe as an ornamental tree, but the European herbalists of the time did not use it. Not until this century did ginkgo become of interest to the Western world. This time, medical scientists focused on selling herb products prescribe the leaf instead of the fruit.
Entry into Modern Medicine
During the 1930s, European interest in the medicinal properties of flavonoids drew researchers' attention to the ginkgo leaf as a particularly rich source of these chemicals.  A concentrated extract of these flavonoids became the basis for study. In 1965, this ginkgo extract was registered for use in Germany. The French medical journal La Presse Medicale devoted its entire September 25 issue to studies of an extract of this remarkable plant.
What Is Ginkgo Used for Today?

In Europe today, ginkgo is primarily used for treating age-related memory loss. In Germany, it is among the top-selling herb products prescribed by physicians. It is also among the most prescribed herbal remedies in France and is widely used in other European countries as well.

In the late 1980s, Germany's Commission E (the official body in charge of validating herbal use) authorized ginkgo for two major purposes: Improving mental function in the elderly and promoting circulation.
In North America, however, ginkgo has not yet been embraced by conventional medicine. However, the herb has become one of the most popular "dietary supplements” on the market.
Strong scientific evidence tells us that ginkgo can improve memory and mental function. Its capacity to do so makes it a nootropic agent, that improves that improves brain function.  At this time, only two nootropic drugs have been approved in the United States to trat Alzheimer’s disease: Cognex (tacrine) and Aricept (donepezil).  If you are interested in reading more about them right now, see chapter 10. In chapters 4 and 9, we'll discuss evidence that ginkgo and certain other natural herbs and supplements may also improve memory and other aspects of mental capacity.
Considerable evidence suggests that ginkgo increases blood circulation in various parts of the body. Until the 1980s, researchers assumed that its beneficial effects on memory were due to increased blood to the brain. Recent research, however, has changed that thinking. Today, research suggests that ginkgo's effect on memory and its effect on circulation are two distinct functions.
Ginkgo's positive effect.
Ginkgo's positive effect on circulation has led to its use in relieving "intermittent claudication,” the severe leg cramps caused by hardening of the arteries. The herb has also been used to treat other conditions in which poor circulation is involved, including impotence, strokes, and the "cold hand" condition known as Raynaud's syndrome. (Please note that combining ginkgo with any of the blood-thinning medications that your physician may prescribe for these conditions may not be safe.)
One study suggests that ginkgo may be helpful in premenstrual tension syndrome (PMS). It has been also recommended for a number of other conditions such as allergies, asthma, and macular degeneration of the eye, although little evidence supports these uses.
An article published in Time magazine on November 3, 1997, has done much to boost public awareness of Ginkgo biloba. Time reported the results of a study published in the Journal of the American Medical Association (JAMA). Known as the Le Bars study for its main author, this research examined the use of a special ginkgo extract in treating Alzheimer's disease and age-related memory loss. This study was especially notable to the American medical community since it was performed at six medical centers across the United States, enrolling a total of more than 300 patients. The results led to considerable excitement among the conventional medical community about ginkgo's potential. Ginkgo is now well on its way toward being an accepted medical treatment in this country.

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